Experimental Mid-Infrared Absorption (84%) of Single-Layer Graphene in a Reflective Asymmetric Fabry–Perot Filter: Implications for Photodetectors

Abedin Nematpour,Nicola Lisi,Maria Luisa Grilli,Rosa Chierchia,Laura Lancellotti

doi:10.1021/acsanm.0c03010

Abstract

There is a growing interest toward graphene and 2D materials for their exceptional geometrical, optical, and electronic features, which make them unique for photonic and optoelectronic applications...

Highlights

Optical absorption is a crucial parameter in many photonics devices such as solar cells, photodetectors, thermal emitters, sensors, and so forth.[1−4] Recently, graphene and 2D materials emerged as promising candidates for a vast range of photonic and optoelectronic applications,[5−10] including those applications demanding high light absorption such as photodetection,[11,12] light modulation,[13,14] and 2D energy conversion devices, which were predicted to achieve 5−10% sunlight absorption in 1 nm thickness.[15]
Perfect absorption or large absorption values in graphene and 2D materials are, quite challenging.[19−21] In general, narrowband absorbers are desirable for sensors and absorption filters,[6] wideband absorbers are desirable for energy harvesting applications,[5,22] while either wide and narrow wideband absorbers can be suitable for specific imaging applications
ACS Applied Nano Materials www.acsanm.org passive optical absorbers with absorption up to 50% were fabricated by our group[41,42] by embedding chemical vapour deposition (CVD) graphene inside FP structures different from the optimized structure, working in reflection mode, which we propose here

Summary

Introduction

Optical absorption is a crucial parameter in many photonics devices such as solar cells, photodetectors, thermal emitters, sensors, and so forth.[1−4] Recently, graphene and 2D materials emerged as promising candidates for a vast range of photonic and optoelectronic applications,[5−10] including those applications demanding high light absorption such as photodetection,[11,12] light modulation,[13,14] and 2D energy conversion devices, which were predicted to achieve 5−10% sunlight absorption in 1 nm thickness.[15]Because of the intrinsic low absorption of 2D materials, strategies must be adopted to enhance their absorption,[15−18] and embedding radiation harvesting 2D devices in resonators may be one of the best viable solutions to approach 100%absorption desirable for many practical applications. Perfect absorption or large absorption values in graphene and 2D materials are, quite challenging.[19−21] In general, narrowband absorbers are desirable for sensors and absorption filters,[6] wideband absorbers are desirable for energy harvesting applications,[5,22] while either wide and narrow wideband absorbers can be suitable for specific imaging applications. Both broadband and narrowband graphenebased photodetectors have been proposed.[6,23]. As far as graphene is concerned, researchers’ efforts have been devoted mainly to pattern exfoliated graphene by e-beam or ion-beam lithography[24,25] or to couple graphene with photonic crystals or metamaterials,[26,27] mostly demonstrating high absorption on small area graphene or on thick, prismbased, broadband optical devices.[28]

Methods

Findings

Discussion

Conclusion